Nasa officials are ensuring “they don’t take their eye off the ball” as astronauts near their return to Earth after travelling deeper into space than anyone before.
The Artemis II crew, who successfully completed a test flight around the Moon, are due to splashdown off the coast of San Diego in California on Friday.
A news conference heard scientists were continuing to learn from the epic voyage that would inform future missions.
This included monitoring the impact of the deep space environment on the three Americans and Canadian aboard the Orion module.
The Goonhilly Earth Station, near Helston, in Cornwall, has been helping track the first Moon mission in more than 50 years.
Lakiesha Hawkins, Nasa’s acting deputy associate administrator for exploration systems development, said: “The mission continues to go well as the crew prepares to transition back to Earth and we get ready for entry day.
“The team is turning our attention to the return and getting the crew safely home.
“Now, because this is a development flight, we are thinking about what we can still learn in the remaining days to better understand the systems and to inform future missions.”
She added: “The experiments about human health are going to give us data that we need to be able to live on the moon longer, as we develop the moon base, and be able to prepare for farther trips, like going on to Mars.
“During Apollo, they didn’t gather this kind of human health data and we can’t get this information during low Earth orbit missions.”
Ms Hawkins went on: “When a mission goes well, it can look like flying to the Moon is easy. It certainly is not.
“We can’t forget that this is a test flight, and are taking everything that we’re learning forward to support the next mission.
“This has been a good mission so far, and we’re nearing the end, having retired a significant number of risks over recent days, but the team remains focused, and we’re making sure that we don’t take our eye off the ball.
“Countless hours of people working together behind the scenes have been preparing for these moments, and people are still giving their all to ensure mission success.
“We continue to improve, to make our ultimate goals of going to the lunar surface, building the moon base and eventually sending the first humans to Mars, a reality.”
The time between re-entering the Earth’s atmosphere and landing in the Pacific Ocean will be about 13 minutes.
Mission flight director Rick Henfling said: “So it’s going to happen pretty quick.”
He added: “It’s very dynamic. So similarly to the launch environment, there’s not a lot of time to react.”
The navy’s USS John P Murtha is currently en route to meet the capsule when it lands.
The last time Nasa sent astronauts to the Moon was as part of the Apollo 17 mission in 1972.
The agency is seeking to return a crew to the lunar surface by 2028, before China does in about 2030.
